This disclosure relates generally to heat sinks and, more particularly, to graphite-based heat sinks and a method and an apparatus for the manufacture thereof.
Heat sinks are generally utilized to provide for the conductive transfer of heat from a heat source (e.g., an electronic component) to a surrounding environment. The conductive transfer of heat from the heat source is most efficient when the heat sink is fabricated from a material having a high coefficient of thermal conductivity to facilitate the rapid conduction of heat from the heat source and its dissipation to the surrounding environment. Such materials include metals such as copper, aluminum, tungsten, molybdenum, alloys of the foregoing metals, and the like. Heat sinks fabricated from such metals and alloys, however, while providing adequate heat transfer capabilities, typically add significant cost and weight to the systems into which they are incorporated.
To alleviate problems associated with weight, the fins of the heat sinks may be made of lighter materials having comparable or improved heat transfer properties. One example of such a material is high conductivity graphite, which may be utilized in a pure form or may be combined with another material to form a graphite composite. However, difficulties associated with the attachment of graphite or graphite composite heat sink fins pose significant obstacles to the use of such materials. In particular, because graphite is not solderable, attachment of graphite fins to a metal base are oftentimes made by alternate means, e.g., with adhesives such as epoxies. Furthermore, because graphite is by nature a brittle material, heat sink fins fabricated from graphite or graphite composites typically crack, chip, or flake, thereby potentially compromising the integrity of the heat sink structure. Chipping or flaking of the graphite or graphite composite material may further raise issues with respect to the contamination of the componentry of the device at which the heat sink is disposed. In particular, chipping or flaking of the graphite materials may contaminate and detrimentally affect the operation of electronic components from which heat must be removed to ensure the proper operation of an electronic system.